Systems and methods for harmonic analysis of soil by converting frequency of operating signal

Abstract

Systems and methods for harmonic analysis of soil are provided herein. Some methods include converting a first frequency of an operating signal into a second, higher frequency relative to the first frequency to create a stimulating signal, transmitting the stimulating signal into soil, and determining attenuation based on a comparison of a responsive signal and the operating signal.

What is claimed is: 
     
       1. A method, comprising:
 selecting a first frequency for use by a sensor; 
 converting an operating signal having the first frequency into a transmitting signal having a second frequency using the sensor, the second frequency being a harmonic of the first frequency; 
 transmitting the signal having the second frequency into soil to produce feedback from the soil; 
 comparing a number of waves of a responsive signal in the first frequency, and derived from the feedback, to a number of waves of the operating signal in the first frequency; 
 determining attenuation by the soil using the comparing of the responsive signal and the operating signal, the attenuation being indicative of clay within the soil; and 
 selectively adjusting pumps and/or valves of an irrigation system to increase or decrease a flow of water to a target area based on the determined attenuation. 
 
     
     
       2. The method according to  claim 1 , wherein the first frequency is at least approximately 50 MHz. 
     
     
       3. The method according to  claim 1 , wherein the second frequency is a second harmonic of the first frequency. 
     
     
       4. The method according to  claim 1 , wherein a volume of clay within the soil correlates to a magnitude of the attenuation. 
     
     
       5. The method according to  claim 1 , further comprising repeating the method for a range of values for the first frequency. 
     
     
       6. The method according to  claim 1 , wherein the sensor is a subterranean sensor comprising harmonic sensor circuitry such that the transmitting of the signal having the second frequency into the soil occurs from at least one level of the sensor below ground. 
     
     
       7. A device, comprising:
 a harmonic sensor circuit that produces an operating signal at a first frequency and emits a stimulating signal at a second frequency that is a harmonic of the first frequency; 
 a processor operatively connected to the harmonic sensor circuit to control the harmonic sensor circuit and receive an output comprising the operating signal and the stimulating signal of the harmonic sensor circuit; and 
 a memory storing instructions, the processor operatively connected to the memory and configured to use the instructions to: 
 control the harmonic sensor circuit to emit the stimulating signal into soil; 
 determine attenuation of the stimulating signal in the soil based on an analysis of a responsive signal that has been converted back into the first frequency relative to the operating signal, including by: 
 comparing a number of waves of the responsive signal in the first frequency to a number of waves of the operating signal in the first frequency; and 
 selectively adjusting pumps and/or valves of an irrigation system to increase or decrease a flow of water to a target area based on the determined attenuation. 
 
     
     
       8. The device according to  claim 7 , further comprising a communications interface operatively connected to the processor so as to receive information from the processor, the processor being configured to transmit a message that is indicative of the attenuation. 
     
     
       9. The device according to  claim 7 , wherein the first frequency is at least approximately 50 MHz. 
     
     
       10. The device according to  claim 7 , wherein the second frequency is a second harmonic of the first frequency. 
     
     
       11. The device according to  claim 7 , wherein a volume of clay within the soil correlates to a magnitude of the attenuation. 
     
     
       12. The device according to  claim 11 , wherein the processor is configured to vary the first frequency over a range of values. 
     
     
       13. The device according to  claim 7 , wherein the harmonic sensor circuit comprises an oscillator and an antenna. 
     
     
       14. A method, comprising:
 converting an operating signal having a first frequency into a stimulating signal having a second frequency higher than the first frequency to create the stimulating signal; 
 transmitting the stimulating signal into soil to produce feedback from the soil; and 
 determining attenuation based on a comparison of a responsive signal, derived from the feedback, and the operating signal including by: 
 comparing a number of waves of the responsive signal in the first frequency to a number of waves of the operating signal in the first frequency; and 
 selectively adjusting pumps and/or valves of an irrigation system to increase or decrease a flow of water to a target area based on the determined attenuation. 
 
     
     
       15. The method according to  claim 14 , wherein determining attenuation comprises comparing waveforms of the responsive signal and the operating signal. 
     
     
       16. The method according to  claim 14 , further comprising selecting the first frequency from a range of frequencies of approximately 50 MHz to 70 MHZ, inclusive. 
     
     
       17. The method according to  claim 14 , wherein a volume of clay within the soil correlates to a magnitude of the attenuation. 
     
     
       18. The method according to  claim 14 , wherein the transmitting of the stimulating signal having the second frequency into the soil occurs from at least one level of a sensor below ground.